


It Came Upon a Midnight Clear

by Astrophilla, sunshinewinchesters



Series: Destiel Christmas Advent Calendar 2015 [20]
Category: Supernatural
Genre: 25 Days of Christmas, 25 Days of Destiel Christmas, Alpha Dean Winchester, Alpha/Beta/Omega Dynamics, Bottom Castiel, Bottom Castiel/Top Dean Winchester, Castiel in Heat, Christmas, Destiel Advent Calendar 2015, Explicit Sexual Content, Knotting, M/M, Mates, Mating Cycles/In Heat, Omega Castiel, Omega Verse, Overprotective Dean, Protective Dean Winchester, Smut, Top Dean, True Mates
Language: English
Status: Completed
Published: 2015-12-21
Updated: 2015-12-21
Packaged: 2018-05-08 02:58:03
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,743
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5480738
Author URL: https://archiveofourown.org/users/Astrophilla/pseuds/Astrophilla, https://archiveofourown.org/users/sunshinewinchesters/pseuds/sunshinewinchesters
Summary: <blockquote class="userstuff">
              <p>Dean and Castiel are at a Christmas party when Castiel goes into heat.</p>
            </blockquote>





	It Came Upon a Midnight Clear

**Author's Note:**

> Written by sunshinewinchesters  
> Beta'd by Astrophilla
> 
> Type: Omega Verse AU, established (mated) Castiel/Dean
> 
>  
> 
> **The twentieth installment of our Destiel Advent Calendar!**

“Dean.” The alpha looks away from Benny, pausing the conversation as his ears prick and the nervous scent of his omega hits him all at once. Except the scent isn’t purely nervous, though that’s definitely a component of it. Castiel smells fucking _amazing_ , even more so than usual, the heady, sweet scent of honeysuckle and cloves sending a jolt through him and igniting him from within. Beneath the anxious scent is that positively ambrosial one, thick and delicious, the one that Dean could smell from miles away: Cas is going into heat. And holy fuck, Dean’s body doesn’t care that he’s in the middle of a crowded party, mid-conversation with an old friend. He’s already getting hard just from the tantalizing scent. Dean blinks rapidly, trying desperately to clear his mind and focus on anything that isn’t desire burning low in his belly. Cas’ eyes are wide, the bright blue of them worried, and he clutches at Dean’s shirt tightly with his fingers, swallowing hard. “Dean, I lost track of what day it is, I didn’t take my suppressants….” Fuck. Cas’ voice is deep and low, the gravel-and-satin quality exactly that of what he uses when they’re between the sheets. _Focus, Winchester!_ Dean internally growls to himself. Cas needs him, Cas is worried, Cas is going into heat and they are surrounded by other alphas who will no doubt start picking up the scent, if they haven’t already. 

“It’s okay, Cas, we’re gonna get out of here. Don’t worry, I’ve got you, I’ll take care of you,” Dean promises, tightening the arms he has around his waist. He looks back to Benny, nodding at him with a smile.  
“It’s been great talking to you, man, but we gotta go.” Benny’s eyebrows furrow in confusion and Dean remembers that since his friend is a beta, he’s not quite as sensitized to the situation. He gestures at Cas, who is now clinging to him and hiding his face against Dean’s neck.  
“We gotta hit the road. I’ll see you around!” Dean would slap Benny on the back as a goodbye, but he can’t bear to remove either of his arms from around Cas.  
“Ah, gotcha. Have a good night, brother. You too, Castiel,” Benny smiles and pats Dean on the shoulder as he starts to guide Cas towards the door.  
“You okay, buddy?” Dean whispers, lips pressed against Cas’ ear as he ducks his head to press a kiss to his temple. Cas’ skin is hot beneath his lips, already sweltering with his heat. “You’re feeling a little too warm. We gotta get you home.” Concern washes through him and he feels two all-consuming desires battling for dominance inside him: the need to protect and comfort his omega, who is clearly in distress at being so vulnerable in an overcrowded room teeming with alphas, and the desire to rip away Cas’ clothes and give him exactly what his body desperately needs. The former wins out, of course, and Dean pulls Cas closer to him, shouldering through the throngs of people and continuing to whisper soothing things into his omega’s ear. 

Dean shoves past a particularly large man blocking their way, muttering an apology under his breath as he makes a beeline for the door. He’s on full alert, sending his protect-provide-defend instincts into overdrive, body fully conscious of all the threats to his omega. There’s so many other alphas here, and while the rational part of Dean’s brain knows it shouldn’t be anything to worry about, his instincts are fighting him on remaining calm and unperturbed. “Hey, watch where you’re fucking going,” the large man he’d bumped into growls, turning around to face him. Fuck. This is _not_ the shit Cas needs right now, the man better back the fuck up or Dean is gonna be having some serious problems with him. More importantly, he needs to get Cas back home as soon as possible and away from everyone here, where he can take care of him like every fiber of his being is pining to do. Cas shudders against him, squeezing closer, and Dean puts himself between the alpha challenging him and Cas, anger flaring through him at the confrontation. Despite the sudden urge to beat the living shit out of the man, Dean keeps his mind focused on his priorities. 

“I said sorry. We’re just trying to leave, I’m not looking for any trouble,” Dean grits out, breathing steadily in and out through his nose to keep his temper under control. The scent of hostile alpha, pungent and sour, is raising his hackles and making him pull Cas closer behind him, keeping him well away from the man. They stare eachother down, the man puffing out his chest and trying to square his shoulders while Dean glares back, anger rolling off him in waves. Cas’ feverish heat is soaking in through his clothes and the poor thing is shaking; the start of his heats are always brutal, and Dean wants more than anything to have him tucked safely into bed, not here and dealing with this knothead of all things. “So if you’ll excuse us,” Dean shoulders past, clenching his jaw against the urge to growl and doesn’t allow even an inch of space between him and his omega. Cas’ scent is overpowering now, so beautiful and heady that it’s creating a positive feedback loop in Dean’s brain. The biofeedback and its viscerally satisfying effects are probably the main reasons for his ability to turn and walk away instead of give in and fight; well, that and the close hold he has on his instincts, doing his best to not let them get out of hand in such a volatile situation. Cas shudders again in his arms, tilting his head back to look up at him.  
“Dean.” His eyes are too wide, his skin flushed with heat, lips bitten and red and fuck if that doesn’t heighten everything Dean’s feeling all at once.  
“I got you, shhh,” Dean murmurs, kissing the top of his head as he escorts him to the door. 

“What makes you think you can just push your way through and walk away like you own the fucking place?” The huge alpha spits, wrapping a meaty hand around Dean’s forearm and yanking them to a stop. Something inside Dean _snaps_.  
“I said fuck off!” Dean snarls, letting go of his omega just long enough to pull his fist back and let it snap forward with all his force to bear, colliding with the douchebag’s nose. There’s the sound and feel of cartilage crunching and then an outraged roar, equal parts pain and fury. Dean wants nothing more than to keep going, to keep hitting him until he’s a bloodied, unconscious heap on the ground, but he knows that isn’t the right thing to do. He’s still in control, so he’s going to take Cas and get the hell out of here before things get worse. He always becomes extra violent when he feels like Cas is threatened, as every alpha is when they sense their mate is in danger, but it isn’t an excuse to become completely unhinged when the alpha hasn’t done anything to his omega. Dean isn’t gonna stick around long enough for him to try. Out of his peripheral, he notes that a crowd has gathered around them, reeking of horny alpha, and it’s driving him nearly insane. “C’mon, buddy, let’s get out of here,” Dean grits out, securing his arms around Cas, who squeezes close and nods, eager to leave. 

The man doesn’t follow them, and for that Dean is glad. He knows he’s intimidating when situations like these arise, he sure as fuck knows how to handle himself in a fight and it clearly shows. The fact Dean caved in that guy’s nose too probably helped—either way, Dean is just glad to get Cas away from all of the knotheads closing in. Dean leads them out into the cold night air, hearing Cas’ audible sigh of relief and pulling him closer, pressing a kiss to the top of his head. “You’re okay, shhh, you’re okay. I’m gonna get you home and then I’m gonna take care of you,” Dean promises, opening up the passenger side door of his Baby and helping Cas inside. his poor omega looks fevered, eyes too bright, a hectic crimson blush over his cheekbones and his skin hot as a coal stove. He looks up at Dean and squeezes his hand, licking his chapped lips and squirming uncomfortably where he slumps against the bench seat. Dean hurries to get behind the wheel and start the car, and then they’re off, Dean speeding ten over to make it home as quickly as possible. Cas scoots over so he’s pressed up against Dean and damn is that distracting, especially when he can smell the sugar-sweet tang of slick, the honeyed musk of his arousal and just the overarching decadent scent of him in heat. It’s doing all kinds of things to him and it takes nearly all of his willpower to not pull over and take care of Cas now, laying him down on the backseat and—

“You’re drifting into the other lane, Dean,” Cas pants, gently guiding Dean’s hands on the wheel to steer them back into their lane.  
“Fuck,” Dean gasps belatedly, jerking the wheel and over-correcting. “Good thing we’re almost home, we’re in no condition to be on the road.” Cas chuckles and the sound is music to Dean’s ears. The alpha runs a hand through his omega’s sweat-damp hair, biting at the inside of his cheek as the electric feel of skin on skin sends a jolt to his rock-hard boner, which strains uncomfortably against his jeans. This has to be some sort of torture, smelling both of their arousal, having his omega in need and wanting him just as bad as he wants his mate. All he can do is keep comforting Cas and race to get home, internally praying that no cop chooses now to pull him over for speeding like he’s in a car chase. “S’okay, Cas, I’ve got you. We’re almost home.” When their house finally comes into view, the scent of Cas’ relief matches the wave of it that rushes through him. He hurriedly parks Baby and before he can even pocket the keys, he’s got an armful of hot, desperate, heat-struck omega, mouthing at his neck and slipping his hands past the waistband of Dean’s jeans. Dean moans, gently tilting Cas’ chin up so that he can seal their lips, Cas eagerly opening and allowing Dean to ravage his mouth with his tongue. Without breaking the kiss, Dean swings Cas into his arms and carries him out of Baby and up the steps into their home, kicking the door shut behind him. Cas’ fingers make short work of the button and zipper on his jeans and he’s palming Dean’s throbbing cock, as if Dean could get any harder. He feels Cas’ hard length pressing against his abdomen as he carries him into their room and lays him down on their bed. 

“Going into heat on Christmas Eve? Sounds like a gift from Mother Nature herself,” Dean jokes in between kisses, and Cas’ only response is a deep, needy sound in the back of his throat that has Dean actually ripping through Cas’ shirt with two fists bunched in the fabric. He strips off his own pants and boxers, flinging his shirt aside, and lays himself over Cas’ now naked form, both hands entangling with his omega’s and pinning them above his head. Cas writhes beneath him, rutting his hips against Dean’s, desperately seeking friction and Dean isn’t about to make him wait. He reaches down between them, grabbing Cas’ dick and stroking him in that way that he knows drives him crazy, with the twist of his wrist at each upstroke, thumb rubbing over the head of his cock and spreading the precome along his shaft. “You’re beautiful like this, Cas, you’re always so damn gorgeous,” Dean breathes against his omega’s neck, inhaling the aphrodisiac scent of his mate and tonguing over the bite mark scar proclaiming his ownership on Cas’ slender neck. Cas is thrusting into Dean’s fist and twisting his fingers in Dean’s hair, unintelligible pleas escaping his spit-slick, swollen lips. “Shhh, you’re okay, I’ve gotcha,” Dean promises, drawing his mouth back to Cas’ and sucking at his bottom lip while Cas’ tongue plunders the inside of his mouth in turn. 

Cas is a writhing mess under him and the overwhelming scent of slick is intoxicating. Dean can no longer resist; he needs Cas now, as much as Cas needs him. Dean runs his hand along Cas’ side and over his hip, fingers brushing along the slick-soaked insides of his thighs and his dick twinges. Cas is drenched, still thrusting messily into Dean’s fist, and with the other hand, Dean massages at Cas’ entrance, coating his hand in the thick, sweet-smelling substance before sliding his index finger all the way inside. Cas’ moan is loud and obscene and now he’s caught between rutting into Dean’s hand and pressing back against his finger, trying to get it deeper inside him. Dean eagerly obliges, chanting praises into Cas’ mouth as he slips in two more and pumps them in and out, scissoring them and groaning as Cas’ hole tightens against his fingers, the omega now focused solely on letting Dean stretch him open. He quickly locates Cas’ prostate out of memory and brushes his fingers over it, causing Cas to arch his back off the sheets, Dean’s name pouring from his lips rapid fire. “I gotcha,” Dean promises over and over, slipping his fingers out and lubing up his dick with the abundance of slick. 

Cas is clinging onto Dean with all he has, head thrown back in pleasure as Dean lines up his cock and as slowly as his self control allows pushes himself into Cas, moaning at the hot, wet tightness engulfing him as he bottoms out, tight balls flush against the slick-drenched globes of his ass. “Dean, Dean, please,” Cas cries, spreading his legs wider and kissing Dean like his life depends on it, sucking at Dean’s tongue as Dean starts to thrust.  
“So fucking beautiful, Cas. So good for me,” Dean gasps breathlessly into Cas’ mouth, snapping his hips forward, and acute needs takes over him as well. They’re moaning each other’s names unabashedly, Cas’ tight hole clenching around Dean with every relentless thrust, and the sight of Cas’ beautiful face contorted in bliss, need, and pleasure, lips slightly parted and bright red, eyes gazing up at him like he hung the sun and moon in the sky is enough to send the heat in Dean’s belly coiling lower, building and building.  
“My alpha, my Dean,” Cas breathes in between their messy kisses, voice completely wrecked, hips stuttering against Dean’s hand. Dean jacks him double time right as the head of his cock hits Cas’ prostate dead on, and now that he’s found that special spot, he nails it ruthlessly. He’s so close, his knot swelling and catching at Cas’ tender rim, the pleasure intensifying to levels that have Dean seeing stars, between being awestruck by everything about his mate, his omega, his Cas. Cas chokes out incoherent noises, eyes rolling and back arching once more off the bed as his orgasm crashes through him, shouting Dean’s name as thick ropes of come spurt from his dick and paint their stomachs. Dean is only seconds behind, the sight of Cas in the throes of pleasure pushing him over the edge, the pleasure cresting and ripping through him from fingertips to toes as he pops his knot, Cas jerking from over-pleasure as Dean’s release fills him full.

“My Cas, my beautiful mate,” Dean pants against Cas’ throat, collapsing on top of his omega, both of their chests heaving as they ride out the aftershocks of their orgasms together. Dean wraps his arms tight around Cas, kissing him deep and slow, the drag of his tongue over the roof of Cas’ mouth lingering and indulgent. “Remind me to thank Mother Nature again, couldn’t ask for a better timing,” Dean hums. Cas’ lips curl into a smile against his and his mate cups his face between his palms, gazing affectionately into his eyes.  
“Merry early Christmas, beloved.” Dean chuckles, unable to stop himself from ducking his head to kiss Cas again.


End file.
